Television coding system with channel level identification
US4323922A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1979 |
| Grant date | Apr 6, 1982 |
| Priority date | — |
| Expiry date | Dec 17, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/162
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A converter/decoder for use in subscription television includes means for converting any input TV channel to a predetermined output channel. Decoding means are connected to the converter at its output for decoding the selected output channel. The decoder is enabled in response to data carried on the TV signal which describes the program level of the particular selected channel. The means for enabling the decoder includes a comparison circuit which compares the television signal program level data with authorization data and performs an enabling function when there is correspondence between the two data entries. The authorization data may be received by the converter/decoder simultaneously with the program level data, but at a frequency other than that of the television signal, for example, at a frequency in the FM band.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.